Bringing in my own communion bread to mass

So I've been thinking of visiting other churches to see how they do their worship, and so on. And I kind of came across the question that if I go to a church such as a Catholic parish that doesn't recognize me as being able to take communion but I still need to take my communion, how do I go about that? Shall I bring my own bread or what? I want to respect what they believe but also want to stay true to what I believe.